I have a problem about using replaceAll method in my java app. I think there is a compile error, and the code is : public static void main(String[] args) { String Str = " Welcome to Itpro.com please visit programming.itpro.com"; System.out.println(Str.replaceAll(".com", ".net")); } } and output is : We.nete to Itpro.net please visit programming.itpro.net welcome… Read More replaceAll method in java
As far as I understand .NET concepts, the source code is first translated into an Assembly (IL code+meta data), which is compiled to machine code on the target machine with the CLR’s JIT compiler. However I cannot really match these concepts to what I see when working on a C# project. When I build a… Read More Understanding .NET compilation
I am trying to turn a List<String> into a Map<T, String>, with the value of the map being an element contained within the previous List<String>, and the key being some attribute of that String (for example, the length of the String, in which case, T would actually be an Integer). I first attempted to do… Read More Function::identity doesn't work in Collectors.toMap
I am converting a character to a string by concatenating it with an empty string (""). But it results in undefined behaviour or garbage characters in the resultant string. Why so? char c = ‘a’; string s = ""+c; cout<<s<<" "<<s.size()<<"\n"; >Solution : Let’s look at your snippet, one statement or a line at a… Read More Garbage when converting character to string using concatenation
I have written a sub query like this- Select ID, count(*) as cn from xyz group by 1 Results in an output of- ID cn A 3 B 45 Now I am doing this query – SELECT CASE WHEN temp.cn > 10 THEN Count(DISTINCT id) END AS cn_10, CASE WHEN temp.cn <= 10 THEN Count(DISTINCT… Read More Subquery SQL , get the count of ID's based on the subquery results
I want to have a class with a constant pointer to a function as a member. However, I’m instead creating functions with constant return values (a strange feature I just run into while debugging). The troublesome declarations are: // … template<typename T, typename ComparableValue> class TimestampedValueHeap { public: TimestampedValueHeap( const ComparableValue (*)(const T&), const big_unsigned… Read More C++ How to create a constant pointer to a function?
I have an abstract class in my header file: template <class T> class IRepository { public: virtual bool SaveData(Result<T> &r) = 0; //virtual Result<T> & GetData()const = 0; virtual ~IRepository() {} }; I inherit it in the header file itself: template <class T> class Repo1 :public IRepository<T> { public: bool SaveData(Result<T> &r)override; //Result<T> & GetData()… Read More Compilation error – defining a concrete implementation of templated abstract class
I’m trying to filter a List of objects that implements a Interface. And I trying to create a generic method for all the classes. Something like: interface SomeInterface { String getFlag(); } class SomeObject implements SomeInterface { public String getFlag() { return "X"; } } List<SomeObject> someObjectList = new ArrayList<>(); // Compilation error here List<SomeObject>… Read More Java Method receive generic list and returns <capture of ?>
I have three classes: class Operation{ public: virtual bool execute(const Solution& sol, Solution& newSol) = 0; pair<int, int> pair_routes; }; class OperationR : public Operation{ public: OperationR(){}; bool execute(const Solution& sol, Solution& newSol); pair<int, int> pair_routes; }; class OperationD : public Operation{ public: OperationD(){}; bool execute(const Solution& sol, Solution& newSol); pair<int, int> pair_routes; }; The… Read More How can change the value of a member of a base class?
I have this code: typedef struct { int test; } SensorData_t; volatile SensorData_t sensorData[10]; SensorData_t getNextSensorData(int i) { SensorData_t data = sensorData[i]; return data; } int main(int argc, char** argv) { } It compiles with gcc version 8.3, but not with g++. Error message: main.c: In function ‘SensorData_t getNextSensorData(int)’: main.c:8:34: error: no matching function for… Read More indexing an element from a volatile struct doesn't work in C++